This invention relates to a composite molded product comprising a plurality of different materials, particularly to a composite molded product which can be used as a button of electric devices and a method of manufacturing the same.
A composite molded product in which a thermoplastic resin material and a thermoplastic elastic material are joined has been utilized for, for example, as a button of electric devices such as a portable telephone, a personal computer, etc. This composite molded product comprises a frame body comprising a thermoplastic resin material and a button portion comprising a thermoplastic elastic material, and a movable pressing portion and a flange portion joining to the frame body are provided at the button portion.
Such a composite molded product has been manufactured by fusion bonding the thermoplastic resin material and the thermoplastic elastic material in a mold using a two-color molding machine.
However, in the conventional composite molded product used for a button, the contacting surface of the thermoplastic resin material and that of the thermoplastic elastic material are all joined so that it may sometimes cause disadvantages. Such a problem is that deflection at the flange portion of the button portion is little whereby stroke at the pressing portion cannot be made large.